The present invention relates to a hinge. More particularly this invention concerns an adjustable hinge assembly for mounting the movable back part on the fixed seat part of an automotive-vehicle seat.
In a two-door automotive vehicle it is necessary to pivot the back part of each of the front seats forwardly in order to gain access to the back seat of the vehicle. To this end the back part is connected via a hinge assembly to the seat part of the motor-vehicle seat.
Federal regulations now require that the back part not be pivotal relative to the seat part except during actuation of a release mechanism which normally locks the back part relative to the seat part. This safety feature prevents a passenger or object in the back seat from being thrown against the back part of the front seat during a collision or sudden braking maneuver and pivoting the back part of the front seat forwardly, thereby injuring the front-seat passenger.
In addition it is normally considered necessary to make the back part of the motor-vehicle seat adjustable relative to the seat part, at least with respect to the inclination of the back part relative to the seat part, Thus adjustment mechanism is provided between these two parts which allows the back part to assume any of a plurality of angularly offset rest positions relative to the seat part. Thus, the user can adjust the back part of the seat for the inclination desired.
It is therefore necessary that a motor-vehicle seat hinge assembly permit displacement of the back part forward relative to the front part to gain access of the motor vehicle while simultaneously allowing adjustment of the rest position of the back part. Since it is obviously undesirable to have to readjust the rest position of the back part each time it is released and pivoted forward for access to the rear seat, these two functions are normally separate. This can most easily be effected by interconnecting the two seat parts by means of a hinge assembly having two parts which can rotate relative to each other and be fixed in any of a plurality of adjustment positions for establishment of the rest position of the back part. Furthermore, both seat elements are jointly pivotal about another axis which is normally offset from the firstmentioned axis so as to allow pivoting of the back part of the seat forwardly after release of the holding mechanism that normally prevents such forward pivoting. Thus, such a hinge assembly is normally relatively complex and prone to failure.
Another disadvantage of the above-described type of hinge assembly is that the adjustment lever which is actuatable to allow changing of the rest position of the back part relative to the seat part is frequently actuated during pivoting-forward of the back part, so that the seat becomes maladjusted. It has been suggested to overcome this difficulty by mounting the seat-adjustment lever at a distance from the seat hinge and providing mechanism to connect the seat-adjustment lever with the adjustment mechanism in the hinge, but such attempts have only greatly complicated the overall structure. Furthermore, during entry into and exiting from the rear seat the passenger very frequently must scramble over the front seat and, no matter where the adjustment lever is positioned, it runs the risk of being actuated.